Specific aims within the overall objective have been to elucidate (1) the biosynthesis of elastin, (2) properties of the elastin monomer, (3) crosslinkage of elastin and collagen, (4) fine structural organization of aortic fibers, and (5) mechanical properties of aortic components in health and disease. The approach is: (a) to maintain copper-deficient pigs as a source of supply of soluble aortic elastin and collagen and of the partially crosslinked fibrous proteins which composed the vessel wall in this disease; (b) to develop in vitro systems for study of the kinetics and intermediates in biosynthesis of these proteins; (c) to characterize the properties and interactions of soluble elastin and collagen and their reactions with other proteins of the intercellular matrix; (d) to establish the crosslink sequence and enzymes responsible for the stabilization of the fibrous proteins; and (e) to correlate the structural organization by electromicroscopy with the mechanical properties of the diseased vessels.